tty: con3215: drop raw3215_info::ubuffer

clang-struct [1] found raw3215_info::ubuffer unused.

It's actually not used since 2004 when we switched to kernel buffers.

[1] https://github.com/jirislaby/clang-struct

Signed-off-by: "Jiri Slaby (SUSE)" <[e-mail]>
Cc: Heiko Carstens <[e-mail]>
Cc: Vasily Gorbik <[e-mail]>
Cc: Alexander Gordeev <[e-mail]>
Cc: Christian Borntraeger <[e-mail]>
Cc: Sven Schnelle <[e-mail]>
Cc: [e-mail]
Acked-by: Alexander Gordeev <[e-mail]>
Reviewed-by: Ilpo Järvinen <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/s390/char/con3215.c

···
 	wait_queue_head_t empty_wait; /* wait queue for flushing */
 	struct timer_list timer;      /* timer for delayed output */
 	int line_pos;		      /* position on the line (for tabs) */
-	char ubuffer[80];	      /* copy_from_user buffer */
 };
 
 /* array of 3215 devices structures */